Published:2011/5/5 20:50:00 Author:TaoXi | Keyword: electronic attenuation | From:SeekIC
The voltage-controlled amplifier's (VCA) gain is controlled by the voltage, this device can be used in the applications of radio tuner control, automatic audio control, instrumentation preamplifier control, computer acquisition system control, also it can be used as the pulse modulator, the phase detector, the wave filter and the high-precision multiplier.etc. Circuit of the TD4000 is as shown in figure (a); The VCA electronic attenuation circuit is shown in the figure (b), it is an application. When the VCA is used as the electronic attenuator, it's features are better than the mechanical attenuator of the chinese broadcasting system, because it does not has the slip noise, easy to control and the attenuation change is continuous. When you adjust the volume manually, the volume potentiometer only need to use the linear potentiometer with Bell characteristics, even if there is noise in the process of using, you can clear the noise by filter.
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